Design and Application of a High Sensitivity Piezoresistive Pressure Sensor for Low Pressure Conditions

In this paper, a pressure sensor for low pressure detection (0.5 kPa–40 kPa) is proposed. In one structure (No. 1), the silicon membrane is partly etched to form a crossed beam on its top for stress concentration. An aluminum layer is also deposited as part of the beam. Four piezoresistors are fabricated. Two are located at the two ends of the beam. The other two are located at the membrane periphery. Four piezoresistors connect into a Wheatstone bridge. To demonstrate the stress concentrate effect of this structure, two other structures were designed and fabricated. One is a flat membrane structure (No. 2), the other is a structure with the aluminum beam, but without etched silicon (No. 3). The measurement results of these three structures show that the No.1 structure has the highest sensitivity, which is about 3.8 times that of the No. 2 structure and 2.7 times that of the No. 3 structure. They also show that the residual stress in the beam has some backside effect on the sensor performance.

[1]  Wang Yan,et al.  Micromachined beam-diaphragm structure improves performances of pressure transducer , 1990 .

[2]  Zhan Zhao,et al.  An advantageous fabrication technology to integrate pressure sensor into multi-sensor for micro weather station , 2009, 2009 4th IEEE International Conference on Nano/Micro Engineered and Molecular Systems.

[3]  O. Korostynska.  Energy Harvesting Technologies , 2011 .

[4]  Conrad P. Heins,et al.  Applied plate theory for the engineer , 1976 .

[5]  J.T.M. van Beek,et al.  A SOI Pirani sensor with triple heat sinks , 2010 .

[6]  R. Budynas,et al.  Advanced Strength and Applied Stress Analysis , 1977 .

[7]  Roberto Horowitz,et al.  Piezoresistive and piezoelectric MEMS strain sensors for vibration detection , 2007, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[8]  Ralph H. Johnson,et al.  A high-sensitivity ribbed and bossed pressure transducer , 1992 .

[9]  J. Wortman,et al.  Young's Modulus, Shear Modulus, and Poisson's Ratio in Silicon and Germanium , 1965 .

[10]  M. L. Dunbar.  A Novel, Media-Compatible Pressure Sensor for Automotive Applications , 2000 .

[11]  S. Beeby,et al.  MEMS Mechanical Sensors , 2004 .

[12]  E. Bakhoum,et al.  Capacitive Pressure Sensor With Very Large Dynamic Range , 2010, IEEE Transactions on Components and Packaging Technologies.

[13]  J. Greenwood,et al.  A high accuracy resonant pressure sensor by fusion bonding and trench etching , 1999 .

[14]  Chang Liu,et al.  Foundations of MEMS , 2006 .

[15]  M. Ohring.  The Materials Science of Thin Films , 1991 .

[16]  G. Stoney.  The Tension of Metallic Films Deposited by Electrolysis , 1909 .

[17]  Yulong Zhao,et al.  The novel structural design for pressure sensors , 2010 .

[18]  Hiroo Wakaumi,et al.  Smart Sensor Systems , 2013 .

[19]  S. Mijalković,et al.  Semiconductor physical electronics , 1997 .

[21]  A capacitive pressure sensor with a novel multi-layered composite membrane structure fabricated by a three-mask process , 2005, The 13th International Conference on Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05..

[22]  James J. Allen.  Micro Electro Mechanical System Design , 2005 .

[23]  HighWire Press.  Proceedings of the Royal Society of London. Series A, Containing papers of a mathematical and physical character , 1934 .